Improved spiral or winding stair



WILLIAM J.Ku1M,or'N EW YORK, N. Y..V

Letters Patent Nd. 19,985, dated July 14, 1868.

IMPROVED SPIRALVOR WINDING STAIR.'

@in tgehnl durch mit tigen tetters ntmt ma mating/tart nf tigt same.

TO ALL WI-IOM IT MAY CONCERN: l 4

Be it known that I, WILLIAM J. KEIM, of thecity, county, and State of New-York, have invented a new and useful Improvement in Spiral or Winding Stairs; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable`those skilled in the art to make and use the sauie,refer ence being had to the accompanying drawings, forming part of this specification, in whichi Figui-e1 represents a perspective view of my improved cockle-stairs. l

Figures 2 and 3 are detail perspective views of double and treble steps.

.Figure 4 is a plan or top view of a quadruple step. o

Figure' is a plan or top view of the upper end of a. double staircase.

Figure 6 is an inverted plan view of a metallic step. I

Figure 7 is a detail transverse section of the same, taken on thc line a: a', iig. 6.

Similar letters of reference indicate corresponding parte.`

This invent-ion relates to a new method of constructing winding stairs, and consists in so constructing theuiv that by one set of steps two or. more separate stairways can beproduced.

Tl1e,steps,rif made inshape of" straight bars, are perforated through the centre, and secured around a cen-l tral post, that tits through the central hole, so that each end ofthe bar formsa separate step for a separate staircase opposite to another step and stirease formed at the opposite side of the central post.

In the saine manner can treble and quadruple'stairs be made by using steps inwhich three or four arms radiate from the post. l

A, in the drawing, represents a double winding staircase, composed'of steps, a a, that are, as in g. 2,tted around the common centre b, so as to form two sets of stairs.

.The steps a are plates or bars of straight, Sshaped, or other form, perforated in the centre, and are then adjusted, one ahove'thc other, in such a Iuanner that they overlap somewhat, as in iig. f2, the overlapping por- 'tions of two steps being connected by means of pins, nails, or screws, c, or by the haluster of the Vrailing E, as shown. y i

The steps may be made of wood or metal, or of any other suitable material. Ifniade of metal, they may be made as in figs, 6 and 7, each lstep lacing simply a-tl1in plate, a, perforated in the centres with langes, e e, around it, and with diagonal braces, f, as shown, the lower edges of said braces forming, the points ofv contact with the step below.

A staircase thus iliade can be used in buildings of lall classes, in light-houses, or as a look-out tower.

'It is fully strong enough to sustain itself, and will serve to strengthen the building in which it is arranged. When large crowds have to pass up and down, Vone llight may be used for going up and the other for going down,

as indicated in `tig.

B, in fig. 3, represents three-armed steps for a treble'stairease, and C, in iig. 4, a four-armed step for a. quadruple staircase.

If desired, still more arms can be arranged. The'ini'ention can also be applied t0 the construction of other articles which are produced by arranging the plates or stepsaround the central part.

I claim as nemend desire to secure by Letters Patentf- An arrangement of winding steps, constructedinsueh a manner as to give 'two or more light-s'within the same space, substantially as described.' l

W. J.`KEIM. Witnesses: I

WM. F. ltclAuAmi,- ALEX. F. ROBERTS. 

